Colorado State University researchers have come up with a potential solution to blood-clotting and infection in medical implants: ‘superhemophobic' titanium surfaces.
In a study published in the journal Advanced Healthcare Materials, researchers shared the results of a collaboration between the labs of Arun Kota and Ketul Popat of the CSU's mechanical and biomedical engineering departments. Their work blends biomedical engineering with material science, offering a possible way of reducing blood clotting and infections, which are problems for patients requiring medical implants.
Titanium is common to medical devices and the researchers started with sheets of the material to grow chemically altered surfaces capable of creating barriers between the blood and titanium. Kota, Popat, and their colleagues then moved on to conducting experiments to show very low adhesion in platelets, a biological process that promotes blood clots and the eventual rejection of a foreign material like an implant.
Making Blood-Repellent Materials
Using blood-repellent material will appear counterintuitive because the usual approach is to make medical devices for implantation that have an affinity for blood. However, the researchers explained what they're doing as following a key innovation: making a surface so repellent that blood is tricked into thinking that there's no foreign material there at all.
Blood reacting undesirably to foreign material is a problem medical researchers have faced for years. In the case of stents, for instance, they can form blood clots, which leads to obstructions and other conditions that promote embolisms or heart attacks. To address this, patients are put on blood thinners for the rest of their life, and even then, taking medication isn't foolproof.
"The reason blood clots is because it finds cells in the blood to go to and attach," said Popat.
Taking inspiration from how blood flows in vessels, the researchers thought that if they could design a material that has a surface that barely comes into contact with blood, then they could reduce chances of clotting to zero. Clotting occurs as a process, a set of events, and what the researchers are targeting is the first set of these events.
Different titanium surfaces were analyzed for the study to determine which chemistries and textures support ideal platelet activation and adhesion. According to findings, titanium in fluorinated nanotubes provided the best level of protection against blood clots.
For their next step, the researchers are looking into testing their superhemophobic titanium in real medical devices.
Medical Implant Risks
According to the U.S. Food and Drug Administration, reactions to materials used in implants is just one risk of using implantable medical devices. Another area of concern is that the surgical procedure itself to insert the implant carries its own set of risks, like bruising, swelling, redness and pain at the surgical site. Additionally, implants can move, break or completely stop over time, prompting additional surgery to replace or repair the implant.
Those prescribed medical implants are advised to be clear about what they are getting before going under the knife. One way to do that is to ask your doctor questions like is the implant permanent, what material is it made of, and what are its benefits and complications.
